As a conventional aluminium alloy bearing of this type, for example, there have been known bearings disclosed in JP-B2-62-14024 and JP-A-3-168411. The former discloses a bearing comprising a bearing alloy which mainly consists of an Al--Sn alloy and a backing metal plate (or layer) which are bonded through an intermediate bonding layer of low hardness consisting of aluminium or aluminium alloy, and are machined. The latter discloses a bearing comprising an aluminium alloy and a backing metal plate (or layer) having high hardness between which an intermediate bonding layer of slightly higher hardness is interposed, to thereby improve the fatigue strength. However, considering recent demands from the user such as weight reduction and performance improvement of an engine, the fatigue strength provided by the above-mentioned bearing structures tends to be rather insufficient. In addition to the method of using an Al alloy as an intermediate bonding layer, there has been well known a method of nickel plating of an intermediate bonding layer on a backing steel plate (or layer).
The known bearing is excellent in conformability and anti-seizure property which are important characteristics for a slide bearing. However, in accordance with speed increasing and power enhancing developments of internal combustion engines in recent years, a load acting on the bearing increases, which results particularly in problems of fatigue and cracks of the intermediate bonding layer. Moreover, nickel plating is unfavorable in cushion property and hardly satisfactory in respect of conformability of the bearing.